Musannaf Ibn Abi Shayba 37:292

Ali ibn Mushir narrated to us, from al-Walid ibn Jumay', from Abu al-Tufayl, who said: A man from Muharib, called 'Amr ibn Dulay' (or Sulay'), came to Hudhayfah and said to him: "O Abu 'Abd Allah, narrate to us what you have seen and witnessed." Hudhayfah said: "O 'Amr ibn Dulay' (or Sulay'), have you seen Muharib or Mudar?" He said: "Yes." He said: "For Mudar will not cease to kill every believer and persecute them, or Allah, the angels, and the believers will strike them until they do not even control the bottom of a valley. Have you seen Muharib or Qays 'Aylan?" He said: "Yes." He said: "So if you see 'Aylan having descended upon al-Sham, then take your precaution."